Diphthong · i The start is low and front — lower and laxer than /æ/ — with spread lips, then it glides to /ɪ/. All three diphthongs end high, so the start is what distinguishes them. The usual error is dropping the glide and saying a flat /ma/.
Three steps to /aɪ/
Drop the jaw first, then raise it.
A low front start
The jaw drops clearly and the tongue is low and front — lower and laxer than /æ/. Put this drawing next to /æ/: /aɪ/ starts one step lower.
Glide to /ɪ/
The jaw comes back up a little and the mouth narrows, all in one continuous movement. No stop in the middle.
Self-check: a hand under the chin
Say my. The jaw should drop and then rise. If it never moves you are producing a monophthong /a/ — the most common error here.
Articulation (side view)
One speaker, one instant: tongue position and lip shape only. The amber circle marks what to look at; the caption says how it differs from the sound it is usually confused with.
Spelling: i, y and igh
Open-syllable i is /aɪ/; final y in monosyllables is /aɪ/; the whole igh family is /aɪ/.
The final e is silent and the i is /aɪ/. Widest coverage, but exceptions exist (give /ɡɪv/, live /lɪv/).
★ Final y in a monosyllable is /aɪ/ (my, try, why, sky); in a longer word it is /i/ (happy, city). Same position, two sounds — the test is syllable count.
The gh in igh is entirely silent. Very stable — the exact opposite of the /f/ in laugh.
i + nd / ld often reads /aɪ/: find, kind, mind, behind, mild, wild. Per word.
Why learners replace /aɪ/
The nearest L1 diphthong has a much shorter glide.
Glide dropped, monophthong left
my → /ma/, time → /tam/. The highest-frequency error on this page and one of the most audible features of the accent.
The jaw is the test: it must drop and rise. No movement, no glide.
Start too high — /eɪ/ instead
time → /teɪm/, like → /leɪk/. The start has risen to mid-front and collides with /eɪ/.
Compare this drawing with /eɪ/: the start of /aɪ/ is nearly as low as /æ/.
Final y read as /aɪ/ everywhere
After learning my / try / sky, happy becomes /ˈhæpaɪ/.
Syllable count is the rule: one syllable /aɪ/, more than one /i/.
Word list
27 words grouped by where the sound sits in the word. Click a word to hear it. These are recorded as separate words, not cut out of the sentences above — a word cut from a sentence carries its neighbours' transitions and always sounds muddier. All three groups use the same speaker, so what changes between them is position, not voice.
Word-initial9
Word-medial9
Word-final9
Three groups of nine. The initial group (eye, ice, iron, item, idea, island, ivory, idle, ivy) all begin with /aɪ/ — a sparse position, and none of them is guessable from spelling.
Corpus and acoustic measurements
Click any word in a sentence to play from that word. The pale band over the waveform marks the measured boundary of the target word.
Per-token data
Every number below is measured directly from the audio, not hand-annotated.
| Token | Accent | Sex | Target | Word length | aɪ duration | F0 | Pitch range | HNR |
|---|
Where the numbers come from
Every figure on this page can be recomputed from the description below.
Corpus: 12 English sentences synthesised with four American voices (two male, two female), each containing one target word, covering initial, medial and final positions. Audio is 22.05 kHz mono 64 kbps; each clip runs from 1.2 s before to 1.5 s after the target word.
Word boundaries: taken from the engine's word-level timestamps (WordBoundary) and corrected for the fixed offset between the engine timeline and the audio start (estimated per item). The target word is shaded in the waveform.
Phoneme boundaries: measured by forced alignment with the MMS_FA acoustic model. Each character's aligned frame range is kept, then a dynamic program maps the character sequence onto the phoneme sequence (th→θ, ng→ŋ, ck→k). Boundaries fall in the middle of the transition between characters; within-word coverage is 100%. Time precision is the model frame length, 20 ms, and boundaries are taken at midpoints, so effective resolution is about 10 ms.
Pitch: Praat's autocorrelation (to_pitch), 10 ms frame step, search range narrowed to the speaker's estimated range, octave errors removed. «Pitch range» is max minus min F0 within the word.
Why there are no paired differences here: this is a single-phoneme page. Eight other pages are contrast pages (θ/ð, l/r/n, vowel length) where the numbers come from paired words read by one speaker. A single-phoneme page has nothing to compare against — pairing it with a neighbour would measure that neighbour, which belongs to a different page.